Gas cylinder pkl explosion-proof 4 kg blue

PKL Indian gas cylinder refillable 4 kg Indian manufacture company pkl holder of the Saudi quality mark (G) what is the thickness of the metal made from the cylinder 2.3 mm for the 4 kg cylinder what is the welding method a mixture of copper and bronze in a continuous thermal furnace with a protective atmosphere what is the type of safety valve in the cylinder in case of explosion the safety release valve with automatic closing opens between 22-30 bar and closes when higher than 20 bar